[DrivePool fast write speeds 450MB/s, but slower read speeds 250MB/s for multiple files/drives?]

Your setup sounds beefy, by the way! Nice choice on the SN850X NVME SSD. But yeah, your read speeds should definitely be better.

[What is the "seek penalty" mentioned in stablebit drivepool changelog?]

So, the "seek penalty" is basically a measure of how much it'll slow down your system when reading or writing data from/to the disk.

[Any way to "force" DrivePool to balance?]

What worked for me was manually moving some files from the stuffed drive to another one. Just drag and drop.

[Is it possible to import a set of disks into Drivepool that are already spanned via windows?]

You'll likely have to do the manual transfer dance first, move the data into the DrivePool, and then add your drives to the pool.

[Optimize files on NVME for use by video editing software]

I had a similar situation where my video editing projects were eating up a ton of space. What I did was kinda simple but effective. I manually moved the big files to my faster drive whenever I was deep into editing. It was a bit of extra work, but it saved me from running out of space at crucial moments.

I don't think DrivePool can automatically shift files based on what app you're using. It's good for organizing stuff, but not really for on-the-fly changes. I ended up writing a basic script to move my files around when I needed them. It wasn't fancy, but it did the job.

Also, I stumbled upon movavi.com while looking for editing tips. They've got some cool stuff that might help with your workflow. It's worth checking out, especially when you're juggling big files and need some extra help.